Laser chip, light-emitting device, optical module and optical communication system

Abstract

The present disclosure belongs to the technical field of optical communications. Provided are a laser chip, a light-emitting device, an optical module and an optical communication system. The laser chip comprises a substrate layer, a first electrode contact layer, a first electrode layer, an active layer, a ridge waveguide layer, a second electrode contact layer and a second electrode layer, wherein the first electrode contact layer is located on the upper surface of the substrate layer, and the first electrode layer is located on the upper surface of the first electrode contact layer; and the active layer, the ridge waveguide layer, the second electrode contact layer and the second electrode layer are sequentially stacked on the upper surface of the first electrode contact layer. The laser chip comprises a plurality of laser segment and at least one electrical isolation segment in a light transmission direction, and an electrical isolation segment is arranged between two adjacent laser segments, wherein an electrical isolation depth at least extends into the lower surface of the first electrode contact layer, and the plurality of laser segments share the ridge waveguide layer and are used for emitting laser of multiple wavelengths. The use of the present disclosure can solve the problem of electrical signal crosstalk between a plurality of laser segments of a common ridge waveguide layer.

Description

Laser chips, optical transmitter devices, optical modules and optical communication systems

[0001] This disclosure claims priority to Chinese patent application No. 202311291899.2 filed on September 28, 2023, entitled “Laser chip, light emitting device, optical module and optical communication system,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to the field of optical communication technology, and in particular to a laser chip, a light emitting device, an optical module and an optical communication system. Background Art

[0003] Currently, the most widely deployed passive optical networks (PONs) include gigabit-capable PONs (GPONs). With the increase in network bandwidth, 10G PONs and 50G PONs will be deployed in the future. To enable the coexistence of different PON systems, combo optical modules have emerged.

[0004] However, in order to transmit multiple wavelengths, current combo optical modules usually package the laser chip emitting each wavelength separately into a transistor outline (TO), resulting in a high cost of the combo optical module.

[0005] Summary of the Invention

[0006] The present disclosure provides a laser chip, a light emitting device, an optical module, and an optical communication system, which can solve the problem of electrical signal crosstalk easily occurring in multiple laser segments on a common substrate layer in related technologies. The technical solution is as follows:

[0007] In a first aspect, a laser chip is provided, comprising a substrate layer, a first electrode contact layer, a first electrode layer, an active layer, a ridge waveguide layer, a second electrode contact layer, and a second electrode layer;

[0008] The first electrode contact layer is located on the upper surface of the substrate layer, and the first electrode layer is located on the upper surface of the first electrode contact layer;

[0009] The active layer, the ridge waveguide layer, the second electrode contact layer and the second electrode layer are sequentially stacked on the upper surface of the first electrode contact layer;

[0010] The laser chip is a multi-segment laser chip, which includes multiple laser segments and at least one electrical isolation segment in the direction of light transmission. The electrical isolation segment is arranged between two adjacent laser segments, and the electrical isolation depth extends at least to the lower surface of the first electrode contact layer.

[0011] In the solution disclosed herein, the laser chip includes multiple laser segments, each of which is equivalent to a laser. Therefore, the laser chip implements multiple lasers that are integrated together at the chip level. That is, the laser chip that can emit multiple wavelengths is packaged into a light-emitting device. When used in a combo optical module, the number of light-emitting devices can be reduced, thereby reducing the cost of the combo optical module.

[0012] Moreover, the multiple laser segments of the laser chip share the ridge waveguide layer and have the same optical path. Therefore, the laser chip eliminates optical path control components such as combiners and filters in the package, which simplifies the packaging process and reduces packaging costs.

[0013] Moreover, the first electrode layer (such as the N-electrode layer) and the second electrode layer (such as the P-electrode layer) of the laser chip are located on the same side of the substrate layer. If both are above the substrate layer, then the carriers that excite the active layer to emit light do not need to pass through the substrate layer. Furthermore, the substrate layer can be made of a material with a relatively high resistivity and relatively poor conductivity, such as a semi-insulating material (because it is impossible for the material to achieve complete insulation, it is called semi-insulating). The thickness of the other layers growing above the substrate layer is relatively thin, making it easy to electrically isolate them. As a result, two adjacent laser segments are separated by an electrically isolated segment with a relatively high resistivity and a substrate layer with a relatively high resistivity, thereby avoiding the problem of electrical signal crosstalk between the two adjacent laser segments.

[0014] In a possible implementation, the substrate layer is made of a semi-insulating material.

[0015] In the solution disclosed herein, because the first and second electrode layers are located on the same side of the substrate layer, when a modulated signal is applied to the first and second electrode layers, the carriers generated do not need to pass through the substrate layer. Therefore, the substrate layer can be made of a semi-insulating material with relatively high resistivity and relatively low conductivity. Therefore, although the laser chip shares a common substrate layer, and the substrate layer and the first electrode layer are relatively close together, the semi-insulating substrate layer makes it difficult for electrical signals applied to the first electrode layers of different laser segments to crosstalk through the semi-insulating substrate layer.

[0016] In a possible implementation, the first electrode layer and the second electrode layer both have a distance between them at the electrical isolation section.

[0017] In the solution shown in the present disclosure, the first electrode layer and the second electrode layer have a spacing at the electrical isolation section, which can avoid electrical signal crosstalk between electrical signals of different laser segments through the first electrode layer and the second electrode layer.

[0018] In one possible implementation, the first electrode contact layer and the second electrode contact layer both have a spacing, and the spacing of the first electrode contact layer is located opposite to the spacing of the first electrode layer, and the spacing of the second electrode contact layer is located opposite to the spacing of the second electrode layer.

[0019] In the solution disclosed herein, there is a distance between the electrode contact layers of different laser segments, which can prevent the electrical signals of different laser segments from causing electrical signal crosstalk through the first electrode contact layer and the second electrode contact layer.

[0020] In a possible implementation, ions for increasing the resistivity of the electrical isolation section are implanted into the electrical isolation section.

[0021] The implanted ions may be inert ions with relatively high resistivity.

[0022] The solution shown in the present disclosure is that ions with relatively high resistivity are injected into the electrical isolation segment, which can increase the resistivity of the ridge waveguide layer in the electrical isolation segment, the resistivity of the active layer in the electrical isolation segment, the resistivity of the first electrode contact layer in the electrical isolation segment, the resistivity of the grating layer in the electrical isolation segment, and the resistivity of the upper and lower confinement layers in the electrical isolation segment, thereby avoiding electrical signal crosstalk between two adjacent laser segments through the ridge waveguide layer, the active layer, the grating layer, the first electrode contact layer, and the upper and lower confinement layers.

[0023] In a possible implementation, the laser chip further includes at least one light processing segment, wherein the light processing segment is arranged between two adjacent laser segments;

[0024] The light processing section is used to reflect the laser light emitted by the laser section between the light emitting end and the light processing section, and to transmit the laser light emitted by the laser section between the backlight end and the light processing section.

[0025] The solution disclosed herein adjusts the grating period of the grating layer within the optical processing section to reflect laser light emitted between the grating layer and the light-emitting end, preventing it from propagating away from the light-emitting end and affecting subsequent laser light. The grating layer also transmits laser light emitted between the grating layer and the backlight end, allowing this portion of laser light to reach the light-emitting end.

[0026] In a possible implementation, if one of the optical processing segments is disposed between two adjacent laser segments, then the electrical isolation segment is disposed between the laser segment and the optical processing segment;

[0027] If a plurality of light processing segments are arranged between two adjacent laser segments, the electrical isolation segment is arranged between the laser segment and the light processing segment, and between two adjacent light processing segments.

[0028] In the solution disclosed herein, the optical processing segment not only reflects and transmits laser light through the grating layer but also performs other laser processing, such as absorption or amplification, through the active layer. Absorption or amplification in the optical processing segment requires voltage. Therefore, to prevent crosstalk between the voltage applied to the optical processing segment and the voltage applied to the laser segment, and to prevent crosstalk between voltages applied to different optical processing segments, the laser segment and the optical processing segment, as well as between adjacent optical processing segments, are separated by an electrical isolation segment.

[0029] In a possible implementation, the optical processing section is a phase modulation processing section, an electroabsorption processing section, or an amplification processing section.

[0030] The solution shown in the present disclosure is a phase modulation processing segment, which is used to reflect the laser emitted between the phase modulation processing segment and the light output end through the grating layer, and transmit the laser emitted between the phase modulation processing segment and the backlight end, while also improving the single-mode yield of the laser chip.

[0031] Among them, the single-mode yield, also known as the single-mode finished product rate, is that the laser segment of a laser chip is usually required to have only one main mode. If one or some laser segments have multiple main modes, the laser chip is scrapped. The ratio of the number of laser chips that meet the requirement of having only one main mode in each laser segment to the total number of laser chips is the single-mode yield.

[0032] In the solution disclosed herein, the EA processing segment is used to reflect the laser light emitted between the EA processing segment and the light-emitting end through the grating layer, and to transmit the laser light emitted between the EA processing segment and the backlight end. In addition, the EA processing segment can absorb the laser light emitted between the EA processing segment and the light-emitting end through the active layer to prevent the laser light from propagating toward the backlight end and affecting the laser light behind.

[0033] The solution shown in the present disclosure is that the SOA processing segment is used to reflect the laser emitted between the SOA processing segment and the light-emitting end through the grating layer, and transmit the laser emitted by the laser segment between the SOA processing segment and the backlight end. In addition, it can also amplify the laser emitted between the SOA processing segment and the backlight end through the active layer to compensate for the loss of laser generated during transmission.

[0034] In a possible implementation, the laser chip further includes a first electrode pad and a second electrode pad, the first electrode pad is electrically connected to the first electrode layer, and the second electrode pad is electrically connected to the second electrode layer;

[0035] The first electrode pad and the second electrode pad are located on different sides or the same side of the ridge waveguide layer.

[0036] In a possible implementation, the laser chip further includes a buffer layer, where the buffer layer is located between the substrate layer and the first electrode contact layer.

[0037] In a second aspect, a light emitting device is provided, comprising the laser chip according to the first aspect.

[0038] In the solution shown in the present disclosure, the laser chip described in the first aspect is a bare chip. Then, after the laser chip is packaged, it can be used in a light emitting device.

[0039] According to a third aspect, an optical module is provided, wherein the optical module includes the light emitting device according to the second aspect.

[0040] In the solution disclosed herein, the optical module includes the light emitting device, circuit board, and driver circuit described in the second aspect. The optical module can be a transmitting optical module or a receiving optical module. The optical module can be used in PONs or in online fiber optic detection systems.

[0041] In a fourth aspect, an optical communication system is provided, comprising a communication device and the optical module according to the third aspect, wherein the optical module is connected to the communication device in a pluggable manner, or the optical module is integrated in the communication device.

[0042] In the solution shown in the present disclosure, the optical communication system can be a PON system or an online optical fiber detection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] FIG1 is a schematic top view of a laser chip provided by the present disclosure;

[0044] FIG2 is a schematic cross-sectional view of a laser chip provided by the present disclosure at line AA in FIG1 ;

[0045] FIG3 is a schematic cross-sectional view of a laser chip provided by the present disclosure at line BB in FIG1 ;

[0046] FIG4 is a schematic cross-sectional view of a laser chip provided by the present disclosure at CC in FIG1 ;

[0047] FIG5 is a schematic top view of a laser chip provided by the present disclosure;

[0048] FIG6 is a schematic cross-sectional view of a laser chip provided by the present disclosure at line BB in FIG5 ;

[0049] FIG. 7 is a schematic cross-sectional view of a laser chip provided by the present disclosure at CC in FIG. 5 .

[0050] Description of Reference Numerals

[0051] 1. Substrate layer; 2. Buffer layer; 3. First electrode contact layer; 4. First electrode layer; 5. Lower confinement layer; 6. Active layer; 7. Upper confinement layer; 8. Grating layer; 9. Ridge waveguide layer; 10. Second electrode contact layer; 11. Second electrode layer; 12. First electrode pad; 13. Second electrode pad; 14. Insulation layer.

[0052] A, laser section; A1, first laser section; A2, second laser section; B, electrical isolation section; B1, first electrical isolation section; B2, second electrical isolation section; C, optical processing section. DETAILED DESCRIPTION

[0053] Although the description of the present disclosure will be introduced in conjunction with some embodiments, this does not mean that the features of this application are limited to the embodiments. On the contrary, the purpose of introducing the application in conjunction with the embodiments is to cover other options or modifications that may be extended based on the claims of the present disclosure. In order to provide an in-depth understanding of the present disclosure, the following description will contain many specific details. The present disclosure can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present disclosure, some specific details will be omitted in the description. It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other unless there is a conflict.

[0054] In the embodiments of the present disclosure, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of the features.

[0055] This embodiment relates to a laser chip, which can be used in an optical module. The optical module can be a combo optical module capable of transmitting and receiving lasers of multiple wavelengths.

[0056] In order to achieve the emission of lasers of multiple wavelengths, a Combo optical module may include multiple laser chips, each of which emits lasers of one wavelength. However, since this Combo optical module includes multiple laser chips and each laser chip is packaged into a TO, the manufacturing cost is relatively high.

[0057] Another type of Combo optical module may include a laser chip, which is multi-segment, and each segment is used to emit laser light of a different wavelength. This multi-segment laser chip structurally includes at least an N-electrode layer, a substrate layer, a lower confinement layer, an active layer, an upper confinement layer, a grating layer, a ridge waveguide layer, a P-type doped ohmic contact layer, and a P-electrode layer, which are stacked in sequence from bottom to top. However, this multi-segment laser chip usually adopts a common N-electrode layer. When a modulated signal is added to the N-electrode layer, there is a problem of signal crosstalk. For example, a modulated signal loaded on the N-electrode layer at a certain segment will crosstalk to the N-electrode layer at another segment. Even if the N-electrode layers of this multi-segment laser chip are independent of each other, there is still a problem of signal crosstalk for the following reasons:

[0058] In order for current to flow between the P-electrode layer and the N-electrode layer to stimulate the active layer between the P-electrode layer and the N-electrode layer to emit light, all layers between the P-electrode layer and the N-electrode layer, including the substrate layer, must have good conductivity. For example, the substrate layer is usually made of N-InP. However, once the substrate layer has good conductivity, the problem of electrical signal crosstalk will occur. For example, the modulated signal loaded on the N-electrode layer at one section will pass through the substrate layer and crosstalk to the N-electrode layer at another section.

[0059] Moreover, even if ion implantation is performed on the lower surface of the substrate layer to increase the resistivity of the substrate layer, the thickness of the substrate layer is relatively thick and the depth of ion implantation is relatively shallow. As a result, the electrical signal applied to the N-electrode layer will still pass through the substrate layer with good conductivity and flow to other laser segments, causing electrical signal crosstalk.

[0060] In order to solve the above problem, this embodiment provides a laser chip, which can specifically be a bare laser chip before packaging.

[0061] As shown in FIG1 , which is a top view schematic diagram of a laser chip, the laser chip is a multi-segment laser chip, including multiple laser segments A, each laser segment A outputs a laser of one wavelength, and thus the laser chip can output lasers of multiple wavelengths.

[0062] It should be noted that for ease of description, the figures of this embodiment illustrate an embodiment including two laser segments A. The case of including more laser segments A is similar and will not be illustrated one by one. For ease of description, as shown in FIG1 , the two laser segments A included in the laser chip can be respectively referred to as the first laser segment A1 and the second laser segment A2.

[0063] As shown in Figure 1, because the laser chip is packaged as a single light-emitting device, its application in combo optical modules can address the high cost of combo optical modules. Furthermore, because the laser chip's P-electrode and N-electrode layers are located on the same side of the substrate layer, the carriers that excite the active layer to emit light do not need to pass through the substrate layer. Consequently, the substrate layer can be made of a material with a high resistivity and poor conductivity. The other layers of the laser chip are relatively thin, making electrical isolation easier. This, in turn, addresses the signal crosstalk issue that occurs when a modulated signal is applied to the N-electrode layer.

[0064] The structural features of the laser chip are introduced below. Since the layers of the laser chip in the thickness direction (i.e., the z direction in Figure 2) are the same, in order to better introduce the laser chip, the structural features of the laser chip in the z direction are first introduced, and then the features of the multi-segment laser chip are introduced.

[0065] FIG2 is a schematic cross-sectional view of a laser chip, specifically a schematic cross-sectional view along line AA in FIG1 .

[0066] As shown in FIG. 2 , the laser chip includes a substrate layer 1 , a first electrode contact layer 3 , a first electrode layer 4 , an active layer 6 , a ridge waveguide layer 9 , a second electrode contact layer 10 and a second electrode layer 11 .

[0067] Continuing to refer to Figure 2, the first electrode contact layer 3 is located on the upper surface of the substrate layer 1, the first electrode layer 4 is located on the upper surface of the first electrode contact layer 3, and the active layer 6, the ridge waveguide layer 9, the second electrode contact layer 10 and the second electrode layer 11 are stacked in sequence on the upper surface of the first electrode contact layer 3.

[0068] In one example, substrate layer 1 serves as the base of the laser chip. Carriers generated by the modulated signal applied to first electrode layer 4 and second electrode layer 11 flow between second electrode layer 11 and first electrode contact layer 3 without passing through substrate layer 1. Therefore, substrate layer 1 can be made of a semi-insulating material (referred to as a semi-insulating material because it cannot achieve complete insulation) with relatively high resistivity and relatively poor conductivity. For example, substrate layer 1 can be made of indium phosphide (InP).

[0069] The first electrode layer 4 may be an N-electrode layer, and the second electrode layer 11 may be a P-electrode layer. Then, the first electrode contact layer 3 where the first electrode layer 4 is located may be an N-type ohmic contact layer, and the second electrode contact layer 10 may be a P-type ohmic contact layer.

[0070] In one example, the electrode contact layer is typically a compound formed by elements from Group III and Group V in the periodic table, and thus may also be referred to as a Group III-V compound. Thus, the N-type ohmic contact layer is an N-type doped Group III-V compound, and the P-type ohmic contact layer is a P-type doped Group III-V material.

[0071] The active layer 6 is a light-emitting layer capable of emitting laser light. For example, it can be a multi-quantum well layer, which is used to excite laser light under the action of an electric field. The ridge waveguide layer 9 is used to form an optical path, allowing the laser light excited by the active layer 6 to propagate along the direction confined by the ridge waveguide layer 9.

[0072] Referring to Figure 2, when a modulation signal is loaded on the first electrode layer 4 and the second electrode layer 11, because the first electrode layer 4 and the first electrode contact layer 3 are adjacent to each other, and the resistivity of the first electrode contact layer 3 is relatively small and the conductivity is relatively good, an electric field can be formed between the second electrode layer 11 and the first electrode contact layer 3, and the carriers enter the active layer 6, causing the active layer 6 to excite laser light.

[0073] Continuing to refer to FIG. 1 , the laser chip further includes a first electrode pad 12 and a second electrode pad 13 , wherein the first electrode pad 12 and the second electrode pad 13 are mainly used for punching gold wires thereon to electrically connect with a peripheral driving circuit.

[0074] The first electrode pad 12 and the second electrode pad 13 may be arranged on different sides of the ridge waveguide layer 9 (see FIG. 1 ), or may be arranged on the same side of the ridge waveguide layer 9 .

[0075] In one example, the first electrode pad 12 is electrically connected to the first electrode layer 4, and the second electrode pad 13 is electrically connected to the second electrode layer 11. In this way, the drive circuit outside the laser chip can apply the modulation signal to the first electrode layer 4 through the first electrode pad 12 and to the second electrode layer 11 through the second electrode pad 13.

[0076] It should be pointed out that the first electrode layer 4, the second electrode layer 11, the first electrode pad 12 and the second electrode pad 13 are all metal layers. Therefore, as shown in Figure 1 and with reference to Figure 2, the first electrode layer 4 and the first electrode pad 12 are integrally formed, and the second electrode layer 11, the second electrode pad 13 and the connecting layer between the second electrode layer 11 and the second electrode pad 13 are integrally formed.

[0077] In one example, since the first electrode contact layer 3, the active layer 6, the ridge waveguide layer 9, and the lower confinement layer 5, the upper confinement layer 7 and the grating layer 8 mentioned below all have good conductivity, in order to limit the carriers to flow between the first electrode contact layer 3 and the second electrode layer 11, accordingly, as shown in FIG2 , the laser chip also includes an insulating layer 14. The material of the insulating layer 14 can specifically be silicon dioxide. As shown in FIG2 , the lower confinement layer 5, the active layer 6, the upper confinement layer 7, the grating layer 8, the ridge waveguide layer 9 and the left and right sides of the second electrode contact layer 10, as well as the lower surface of the second electrode pad 13 are all arranged with an insulating layer 14.

[0078] In one example, in order to make the laser chip output a single longitudinal mode laser mode, accordingly, as shown in Figure 2, the laser chip also includes a grating layer 8, wherein the grating layer 8 can be located between the active layer 6 and the ridge waveguide layer 9, or between the active layer 6 and the first electrode contact layer 3.

[0079] In this way, the grating layer 8 is used to select the mode of the output laser, so the grating layer 8 can also be called a mode-selective grating. By adjusting the grating period of the grating layer 8, the laser chip can output single longitudinal mode laser light.

[0080] In one example, the structure of the grating layer 8 can be a distributed feedback (DFB) grating with phase shift, or an asymmetric corrugation-pitch-modulated (ACPM) grating, or other grating structures with the function of selecting a single longitudinal mode.

[0081] In one example, in order to confine carriers in the active layer 6 , the laser chip further includes a lower confinement layer 5 and an upper confinement layer 7 , as shown in FIG. 2 , wherein the active layer 6 is located between the lower confinement layer 5 and the upper confinement layer 7 .

[0082] In one example, in order to better grow other layers on the upper surface of the substrate layer 1 , the laser chip may further include a buffer layer 2 as shown in FIG. 2 . The buffer layer 2 is located between the substrate layer 1 and the first electrode contact layer 3 .

[0083] Then, referring to Figure 2, the buffer layer 2 and the first electrode contact layer 3 are superimposed on the upper surface of the substrate layer 1 in sequence, the first electrode layer 4 is located on the upper surface of the first electrode contact layer 3, and the lower restriction layer 5, the active layer 6, the upper restriction layer 7, the grating layer 8, the ridge waveguide layer 9, the second electrode contact layer 10 and the second electrode layer 11 are superimposed and arranged on the upper surface of the first electrode contact layer 3 in sequence.

[0084] Insulating layers 14 are arranged on the left and right sides of the lower confinement layer 5 , the active layer 6 , the upper confinement layer 7 , the grating layer 8 , the ridge waveguide layer 9 and the second electrode contact layer 10 , as well as the lower surface of the second electrode pad 14 .

[0085] The above are the characteristics of the laser chip in the thickness direction (ie, the z-axis direction). The following will introduce the characteristics of the laser chip in the length direction (ie, the y-axis direction).

[0086] FIG1 is a schematic top view of a laser chip, FIG3 is a schematic cross-sectional view of the laser chip, and is a schematic cross-sectional view taken at BB in FIG1 , and FIG4 is also a schematic cross-sectional view of the laser chip, and is a schematic cross-sectional view taken at CC in FIG1 . The filled areas in FIG3 and FIG4 represent ion implantation areas.

[0087] Referring to FIG1 , the laser chip is a multi-segment laser chip, including multiple laser segments A. Each laser segment A is equivalent to a laser. The laser can be a directly modulated laser, and its operating mode is a single main mode, so it can also be called a single longitudinal mode directly modulated laser.

[0088] Since different laser segments A emit lasers of different wavelengths, the laser chip can emit lasers of multiple wavelengths.

[0089] The length of each laser segment A, i.e., the length along the y-axis as shown in FIG1 , can be, for example, between 200 and 300 μm. For example, the length of the first laser segment A1 and the length of the second laser segment A2 are both between 200 and 300 μm.

[0090] In one example, to achieve a single longitudinal mode operating mode for each laser segment A, as shown in Figure 3, the grating layer 8 at the first laser segment A1 serves as a mode-selective grating for the first laser segment A1, enabling the first laser segment A1 to operate as a single longitudinal mode laser in the single longitudinal mode. Similarly, the grating layer 8 at the second laser segment A2 serves as a mode-selective grating for the second laser segment A2, enabling the second laser segment A2 to also operate as a single longitudinal mode laser in the single longitudinal mode. Because the first and second laser segments A1 and A2 operate at different wavelengths, the corresponding grating layers 8 have different periods.

[0091] Furthermore, each laser segment A operates in a single longitudinal mode under the mode selection effect of the grating layer 8. For example, the first laser segment A1 operates at a wavelength between 1480 and 1500 nm and a direct modulation rate of 2.5 Gbit / s, making it a 2.5G direct modulation laser. The second laser segment A2 operates at a wavelength between 1575 and 1580 nm and a direct modulation rate of 10 Gbit / s, making it a 10G direct modulation laser.

[0092] As shown in FIG1 with reference to FIG3 and FIG4 , multiple laser segments A share substrate layer 1 and ridge waveguide layer 9. Therefore, as shown in FIG1 with reference to FIG3 and FIG4 , multiple laser segments A are arranged sequentially along the light transmission direction between the light output end and the backlight end. In other words, these multiple laser segments A are connected in series along the light transmission direction (i.e., the y-axis).

[0093] As shown in FIG1 , the light-emitting end and the backlight end are positioned opposite each other, and the light-emitting end is coated with an anti-reflection film so that the laser light emitted by each laser segment A can pass through the light-emitting end and be emitted from the laser chip.

[0094] For example, the anti-reflection film at the light-emitting end increases the transmittance of both the 1490 nm laser emitted by the first laser segment A1 and the 1577 nm laser emitted by the second laser segment A2.

[0095] The backlight end is coated with a high-reflection film, or the backlight end is a cleavage surface of the laser chip, so that the laser emitted by each laser segment A is reflected when it is transmitted to the backlight end.

[0096] For example, the high-reflection film coated on the backlight end has high reflection for both the 1490nm laser emitted by the first laser segment A1 and the 1577nm laser emitted by the second laser segment A2.

[0097] In one example, in order to achieve that multiple laser segments A share the ridge waveguide layer 9 and have the same optical path but are independent of each other and do not interfere with each other, the multiple laser segments A need to meet at least the following conditions.

[0098] Because multiple laser segments A share a common transmission optical path, in order to prevent high-energy short-wavelength laser light from being absorbed by low-energy long-wavelength laser light during laser transmission, when multiple laser segments A are arranged along the light transmission direction, their operating wavelengths increase sequentially from the light-emitting end to the backlight end of the laser chip. That is, for any two laser segments A, the laser segment A emitting short-wavelength laser light is close to the light-emitting end, and the laser segment A emitting long-wavelength laser light is close to the backlight end.

[0099] For example, as shown in Figure 2, the operating wavelength of the first laser segment A1 is λ1 (such as 1490nm), and the operating wavelength of the second laser segment A2 is λ2 (such as 1577nm). λ1 is smaller than λ2. Then, the first laser segment A1 is close to the light-emitting end, and the second laser segment A2 is close to the backlight end.

[0100] In one example, during laser transmission, for any two laser segments A, the transition energy level difference between the laser emitted by the laser segment A farther from the light-emitting end is much smaller than the energy gap of the laser emitted by the laser segment A closer to the light-emitting end. In other words, for two lasers of different wavelengths, the transition energy level difference of the longer-wavelength laser is much smaller than the energy gap of the shorter-wavelength laser. When the longer-wavelength laser is transmitted to the shorter-wavelength laser, it has little effect on the shorter-wavelength laser, rendering the laser segment A emitting the shorter-wavelength laser essentially transparent to the laser segment A emitting the longer-wavelength laser.

[0101] For example, the transition energy level difference of the 1577nm laser emitted by the second laser segment A2 is Q1, and the energy gap of the 1490nm laser emitted by the first laser segment A1 is Q2. Q1 is much smaller than Q2, so that the 1490nm laser is basically transparent to the 1577nm laser.

[0102] In one example, during laser transmission, in order to avoid the grating layer 8 at the laser segment A close to the light-emitting end, the laser emitted by the laser segment A far from the light-emitting end is filtered out. That is, as shown in FIG3 , in order to avoid the grating layer 8 at the first laser segment A1, the laser emitted by the second laser segment A2 is filtered out. Accordingly, for any two laser segments A, the operating wavelength of the laser segment A far from the light-emitting end is outside the blocking band of the grating layer 8 at the laser segment A close to the light-emitting end.

[0103] For example, as shown in FIG3 , the 1577 nm laser light emitted by the second laser segment A2 is outside the blocking band of the grating layer 8 of the first laser segment A1 , so as to prevent the 1577 nm laser light emitted by the second laser segment A2 from being filtered out by the grating layer 8 of the first laser segment A1 when being transmitted to the first laser segment A1 .

[0104] It should be noted that regarding the relationship between the various layers in different laser segments A, wavelength-dependent layers differ in different laser segments A. For example, the active layer 6 differs in different laser segments A, primarily in composition. Because the upper confinement layer 7 and the lower confinement layer 5 are both related to the active layer 6, the upper confinement layer 7 and the lower confinement layer 5 differ in different laser segments A. Because the grating layer 8 is also related to the operating wavelength of laser segment A, the grating layer 8 differs in different laser segments A, primarily in the grating period; the composition can be the same. Layers independent of wavelength can be the same in different laser segments A. For example, the substrate layer 1, buffer layer 2, first electrode contact layer 3, first electrode layer 4, ridge waveguide layer 9, second electrode contact layer 10, and second electrode layer 11 can all be the same in different laser segments A.

[0105] The above are the conditions that need to be met by multiple laser segments A to realize the common ridge waveguide layer 9. The solution for avoiding signal crosstalk will be introduced below.

[0106] When different laser segments A are loaded with modulation signals, in order to avoid electrical signal crosstalk between different laser segments A, as shown in Figure 1, the laser chip includes at least one electrical isolation segment B, and two adjacent laser segments A are electrically isolated by the electrical isolation segment B, wherein the electrical isolation depth of the electrical isolation segment B at least extends into the lower surface of the first electrode contact layer 3, and the electrical isolation segment B is used to avoid modulation signal crosstalk between adjacent laser segments A.

[0107] The length of the electrical isolation section B, that is, the length along the y-axis in FIG. 1 , may be between 20 and 50 μm.

[0108] Among them, the electrical isolation depth of the electrical isolation segment B, that is, the depth along the z-axis direction in Figure 3, at least extends to the lower surface of the first electrode contact layer 3, for the following reasons (the electrical isolation depth in Figures 3 and 4 extends to the substrate layer 1, and can extend to the interior of the substrate layer 1, or extend to the upper surface of the substrate layer 1).

[0109] As shown in Figure 3, when a modulation signal is applied to the first electrode layer 4 and the second electrode layer 11, carriers flow between the second electrode layer 11 and the first electrode contact layer 3. Therefore, each layer between the second electrode layer 11 and the first electrode contact layer 3 must have good conductivity, while the substrate layer 1 and the buffer layer 2 do not need to have good conductivity. Therefore, if the first electrode contact layer 3, the lower confinement layer 5, the active layer 6, the upper confinement layer 7, the grating layer 8, the ridge waveguide layer 9, the second electrode contact layer 10, and the second electrode layer 11 have good conductivity, then the modulation signals between different laser segments A will crosstalk through these layers. Therefore, the electrical isolation depth of the electrically isolated segment B needs to extend at least to the lower surface of the first electrode contact layer 3, and the buffer layer 2 and the substrate layer 1 can be made of materials with relatively high resistivity.

[0110] In one example, electrical isolation of the electrically isolated segment B may be achieved by removing a metal layer and implanting a resistivity-increasing substance (eg, inert ions).

[0111] The removing of the metal layer includes removing the electrode layer in the electrically isolated section B, or removing the electrode layer and the electrode contact layer in the electrically isolated section B.

[0112] As an example, as shown in FIG4 , there is a spacing between the first electrode layers 4 of two adjacent laser segments A at the electrical isolation segment B. As shown in FIG3 , there is also a spacing between the second electrode layers 11 of two adjacent laser segments A at the electrical isolation segment B.

[0113] For example, as shown in FIG3 , there is a gap between the second electrode layer 11 of the first laser segment A1 and the second electrode layer 11 of the second laser segment A2. As shown in FIG4 , there is also a gap between the first electrode layer 4 of the first laser segment A1 and the first electrode layer 4 of the second laser segment A2.

[0114] 4 , the first electrode layer 4 of the laser chip is removed at the electrical isolation section B to form a gap. As shown in FIG3 , the second electrode layer 11 of the laser chip is removed at the electrical isolation section B to form a gap.

[0115] As another example, as shown in Figure 4, the first electrode contact layer 3 also has a spacing in the electrical isolation segment B, and the spacing position is opposite to the spacing position of the first electrode layer 4. That is, as shown in Figure 4, on the side where the first electrode layer 4 is located, there is a spacing between the first electrode layers 4 of two adjacent laser segments A, and between the first electrode contact layers 3 of two adjacent laser segments A, in the electrical isolation segment B.

[0116] Similarly, as shown in FIG3 , the second electrode contact layer 10 has a spacing, and the spacing position is relative to the spacing position of the second electrode layer 11. That is, as shown in FIG3 , there is also a spacing between the second electrode layers 11 of two adjacent laser segments A, and between the second electrode contact layers 10 of two adjacent laser segments A at the electrical isolation segment B.

[0117] For example, as shown in Figure 3, there is a gap between the first electrode layer 11 of the first laser segment A1 and the first electrode layer 11 of the second laser segment A2, and there is also a gap between the second electrode contact layer 10 of the first laser segment A1 and the second electrode contact layer 10 of the second laser segment A2. As shown in Figure 4, there is a gap between the first electrode layer 4 of the first laser segment A1 and the first electrode layer 4 of the second laser segment A2. On the side of the first electrode layer 4, there is also a gap between the first electrode contact layer 3 of the first laser segment A1 and the first electrode contact layer 10 of the second laser segment A2.

[0118] As shown in FIG4 , on the side where the first electrode layer 4 is located, the first electrode contact layer 3 of the laser chip is removed at the electrical isolation section B, thereby forming a gap. As shown in FIG3 , the second electrode contact layer 10 of the laser chip is removed at the electrical isolation section B, thereby forming a gap.

[0119] Therefore, as shown in FIG3 and FIG4 , since the electrode layer is located on the upper surface of the electrode contact layer, the electrode contact layer can also be removed at the position where the electrode layer is removed to enhance the electrical isolation effect.

[0120] Since the ridge waveguide layer 9 is also conductive, electrical signal crosstalk will occur between adjacent laser segments A through the ridge waveguide layer 9. Therefore, as described above, the electrical isolation segment B also achieves an electrical isolation effect by injecting ions for increasing resistivity.

[0121] The depth of the ion implantation at least extends to the lower surface of the first electrode contact layer 3 , for the reasons mentioned above.

[0122] For example, the electrically isolated section B may be implanted with inert ions for increasing the resistivity of the electrically isolated section B.

[0123] In one example, ions for increasing the resistivity of the electrical isolation segment B may be injected into the electrical isolation segment B multiple times to achieve the resistivity in the electrical isolation segment B and meet the requirement of no crosstalk of electrical signals.

[0124] For example, if the first electrode layer 4 is an N-type electrode layer, the first electrode contact layer 3 is made of an N-type doped III-V compound material, the substrate layer is semi-insulating InP, and the second electrode layer 11 is a P-type electrode layer, the second electrode contact layer 10 is made of a P-type doped III-V compound material. Multiple ion implantations are then performed to increase the resistivity of the N-type doped III-V material within the electrically isolated segment B. The ion implantation depth must at least reach the lower surface of the first electrode contact layer 3 (e.g., it may extend into the substrate layer 1). Multiple ion implantations are then performed again to increase the resistivity of the P-type doped III-V material within the electrically isolated segment B. The ion implantation depth must be at least greater than that of the P-type doped III-V material.

[0125] Based on the above, as shown in FIG3 , the second electrode layers 11 of different laser segments A do not contact each other and are independent of each other, and no electrical signal crosstalk occurs. As shown in FIG4 , the first electrode layers 4 of different laser segments A do not contact each other and are independent of each other, and no electrical signal crosstalk occurs.

[0126] As shown in FIG3 , the second electrode contact layers 10 of different laser segments A do not contact each other and are independent of each other, and cannot cause electrical signal crosstalk. As shown in FIG4 , on the side where the second electrode layer 4 is located, the first electrode contact layers 3 of different laser segments A do not contact each other and cannot cause electrical signal crosstalk.

[0127] Continuing to refer to FIG3 , ions are injected between the ridge waveguide layer 9 and the substrate layer 1 of the electrical isolation segment B to increase the resistivity of the electrical isolation segment B. In addition, the substrate layer 1 and the buffer layer 2 are made of semi-insulating materials. Therefore, the resistivity of the ridge waveguide layer 9, the grating layer 8, the upper confinement layer 7, the active layer 6, the lower confinement layer 5, the first electrode contact layer 3 between the lower confinement layer 5 and the buffer layer 2, and the buffer layer 2 and the substrate layer 1 in the electrical isolation segment B are relatively large, making it difficult for electrical signals to crosstalk through them.

[0128] Therefore, because the resistivity within the electrically isolated segment B is relatively high and the substrate layer 1 and buffer layer 2 are made of semi-insulating materials, the modulation signal applied to the second electrode layer 11 of the first laser segment A1 has difficulty flowing into the second laser segment A2, and the modulation signal applied to the first electrode layer 4 of the first laser segment A1 has difficulty flowing into the second laser segment A2. Similarly, the modulation signal applied to the second electrode layer 11 of the second laser segment A2 has difficulty flowing into the first laser segment A1, and the modulation signal applied to the first electrode layer 4 of the second laser segment A2 has difficulty flowing into the first laser segment A1. This prevents the problem of electrical signal crosstalk between different laser segments A.

[0129] In this way, when driving the laser chip to emit laser light, either differential drive or single-ended drive can be adopted. Differential drive means that the modulation signal is applied to both the first electrode layer 4 and the second electrode layer 11 of the laser segment A. Single-ended drive means that the modulation signal is applied to the second electrode layer 11 of the laser segment A, while the first electrode layer 4 is grounded. Compared with single-ended drive, differential drive helps improve the eye diagram quality of the laser.

[0130] In one example, in order to prevent the laser from being transmitted to the backlight end, accordingly, as shown in Figures 5 to 7, the laser chip also includes at least one light processing segment C, and a light processing segment C is arranged between two adjacent laser segments A. The light processing segment C is used to reflect the laser emitted by the laser segment A located between the light output end and the light processing segment C, and transmit the laser emitted by the laser segment A located between the backlight end and the light processing segment C.

[0131] Figure 5 is a schematic top view of the laser chip, and Figures 6 and 7 are both schematic cross-sectional views of the laser chip, with Figure 6 being a schematic cross-sectional view taken at line BB in Figure 5 and Figure 7 being a schematic cross-sectional view taken at line CC in Figure 5. The filled areas in Figures 6 and 7 represent ion implantation areas.

[0132] As shown in FIG5 , the light processing segment C reflects the laser emitted in front of it and transmits the laser emitted behind it, wherein the area between the light processing segment C and the light output end is referred to as the front of the light processing segment C, and the area between the light processing segment C and the backlight end is referred to as the back of the light processing segment C.

[0133] For example, as shown in FIG5 , the optical processing section C is used to reflect the laser light emitted by the first laser section A1 and transmit the laser light emitted by the second laser section A2 .

[0134] In one example, by adjusting the period of the grating layer 8 within the optical processing segment C, it is possible to reflect the laser light emitted by the laser segment A located between the light-emitting end and the optical processing segment C, while transmitting the laser light emitted by the laser segment A located between the backlight end and the optical processing segment C. Thus, as shown in FIG6 , the grating layer 8 within the optical processing segment C reflects the laser light emitted in front of it and transmits the laser light emitted behind it.

[0135] In one example, the optical processing section C can be located in the electrically isolated section B (not shown). In this case, the optical processing section C only reflects and transmits lasers of different wavelengths through the period of the grating layer 8.

[0136] In another example, the optical processing segment C may not be in the electrical isolation segment B. In this solution where the optical processing segment C is not in the electrical isolation segment B, the optical processing segment C can not only reflect and transmit the laser through the grating layer 8, but also perform phase adjustment, absorption or amplification on the laser through the active layer 6.

[0137] The phase processing, absorption processing, or amplification processing of the optical processing segment C requires the application of voltage. Therefore, in order to avoid crosstalk between the voltage applied to the optical processing segment C and the voltage applied to the laser segment A, and to avoid crosstalk between the voltages applied to different optical processing segments C, the laser segment A and the optical processing segment C, as well as between two adjacent optical processing segments C, are separated by an electrical isolation segment B.

[0138] For example, if a photoprocessing segment C is disposed between two laser segments A, as shown in FIG5 , an electrical isolation segment B is disposed between one laser segment A and the photoprocessing segment C, and an electrical isolation segment B is also disposed between the other laser segment A and the photoprocessing segment C. If multiple photoprocessing segments C are disposed between two laser segments A, an electrical isolation segment B is disposed between each laser segment A and the photoprocessing segment C, as well as between two adjacent photoprocessing segments C.

[0139] As described above, the optical processing segment C can perform phase modulation processing, absorption processing, or amplification processing. Accordingly, the optical processing segment C can be a phase modulation processing segment, an electroabsorption processing segment, or an amplification processing segment.

[0140] In one example, in a solution where a laser chip includes multiple optical processing segments C, each of the multiple optical processing segments C can be one of a phase modulation processing segment, an electroabsorption processing segment, and an amplification processing segment. Alternatively, the multiple optical processing segments C can include two or three of the phase modulation processing segment, the electroabsorption processing segment, and the amplification processing segment.

[0141] The phase modulation processing section is used to reflect the laser light emitted by the laser segment A between the phase modulation processing section and the light output end through the grating layer 8, and transmit the laser light emitted by the laser segment A between the phase modulation processing section and the backlight end, thereby improving the single-mode yield of the laser chip. The single-mode yield, also known as the single-mode finished product rate, is that the laser segment A of the laser chip is generally required to have only one main mode. If one or some laser segments A have multiple main modes, the laser chip is scrapped. The ratio of the number of laser chips with only one main mode in each laser segment A to the total number of laser chips is the single-mode yield.

[0142] For example, as shown in FIG5 , if the optical processing segment C is a phase modulation processing segment, then the optical processing segment C reflects the laser emitted by the first laser segment A1 and transmits the laser emitted by the second laser segment A2 through the grating layer 8, thereby improving the single-mode yield of the laser chip.

[0143] Among them, the electroabsorption (EA) processing segment is used to reflect the laser emitted by the laser segment A between the EA processing segment and the light-emitting end through the grating layer 8, and transmit the laser emitted by the laser segment A between the EA processing segment and the backlight end. In addition, it can also absorb the laser emitted by the laser segment A between the EA processing segment and the light-emitting end through the active layer 6 to prevent the laser from propagating toward the backlight end and affecting the laser behind.

[0144] As shown in FIG5 , if the optical processing segment C is an EA processing segment, then, the optical processing segment C not only reflects the laser light emitted by the first laser segment A1 and transmits the laser light emitted by the second laser segment A2 through the grating layer 8, but also absorbs the laser light emitted by the first laser segment A1 and reflected to the optical processing segment C through the active layer 6 to avoid entering the second laser segment A2 and generating optical crosstalk.

[0145] For example, if the first laser segment A1 emits 1490nm laser light and the second laser segment A2 emits 1577nm laser light, the EA treatment segment reflects the 1490nm laser light and transmits the 1577nm laser light through the period of the grating layer 8. The EA treatment segment also absorbs the 1490nm laser light through the active layer 6, thereby preventing the 1490nm laser light from being transmitted to the emission area of ​​the 1577nm laser light and being absorbed by the 1577nm laser light.

[0146] Among them, the semiconductor optical amplifier (SOA) processing segment is used to reflect the laser light emitted by the laser segment A between the SOA processing segment and the light-emitting end through the grating layer 8, and transmit the laser light emitted by the laser segment A between the SOA processing segment and the backlight end. In addition, it can also amplify the laser light emitted by the laser segment A between the SOA processing segment and the backlight end through the active layer 6 to compensate for the loss of laser light generated during transmission.

[0147] As shown in FIG5 , if the optical processing segment C is an SOA processing segment, then, in addition to reflecting the laser light emitted by the first laser segment A1 and transmitting the laser light emitted by the second laser segment A2 through the grating layer 8, the optical processing segment C can also amplify the laser light emitted by the second laser segment A2 through the active layer 6 to compensate for the optical loss caused by the laser light emitted by the second laser segment A2 when passing through the first laser segment A1.

[0148] For example, if the first laser segment A1 emits 1490nm laser light and the second laser segment A2 emits 1577nm laser light, the SOA processing section, through the period of the grating layer 8, reflects the 1490nm laser light and transmits the 1577nm laser light. The SOA processing section also amplifies the 1577nm laser light through the active layer 6 to compensate for the optical loss caused by the 1577nm laser light being transmitted to the 1490nm laser emission area.

[0149] In one example, the phase modulation processing segment needs to apply voltage to perform phase modulation processing, the EA processing segment also needs to apply voltage to perform absorption processing, and the SOA processing segment also needs to apply voltage to perform amplification processing. Then, as shown in Figures 6 and 7, the optical processing segment C includes a first electrode layer 4, a first electrode contact layer 3, a second electrode layer 11 and a second electrode contact layer 10.

[0150] In order to prevent the voltage applied to the optical processing segment C from crosstalking to the laser segment A, accordingly, as shown in Figures 6 and 7, the laser segment A and the optical processing segment C are also electrically isolated by the electrical isolation segment B. The electrical isolation means are the same as those described above, and reference can be made to the above description.

[0151] If there are multiple optical processing segments C between two adjacent laser segments A, then in order to prevent the voltage applied to one optical processing segment C from crosstalking to another optical processing segment C, the two adjacent optical processing segments C are also electrically isolated by the electrical isolation segment B.

[0152] It should be pointed out that the grating layer 8 at the laser segment A is different from the grating layer 8 at the optical processing segment C. The difference is reflected in the different grating periods. As mentioned above, the grating layer 8 at the laser segment A is used for mode selection, while the grating layer 8 at the optical processing segment C is used to reflect the front laser and transmit the rear laser.

[0153] In one example, regarding the application scenario of the laser chip, the laser chip can be used in any single-wavelength and multi-wavelength scenarios, for example, it can be used in a PON system or in an online optical fiber detection system. This embodiment does not limit the application scenario of the laser chip.

[0154] In this embodiment, the laser chip includes multiple laser segments A, each laser segment A is equivalent to a laser, so the laser chip realizes the integration of multiple lasers at the chip level, that is, the laser chip that can emit multiple wavelengths is packaged into a light emitting device (i.e., a light emitting device). Then, when used in a combo light emitting device, the number of light emitting devices can be reduced, thereby reducing the cost of the combo light emitting device.

[0155] Moreover, the multiple laser segments A of the laser chip share the ridge waveguide layer and have the same optical path. Therefore, the laser chip eliminates optical path control components such as combiners and filters in the package, which simplifies the packaging process and reduces packaging costs.

[0156] Moreover, the first electrode layer (such as the N-electrode layer) and the second electrode layer (such as the P-electrode layer) of the laser chip are located on the same side of the substrate layer. If both are above the substrate layer, then the carriers that excite the active layer to emit light do not need to pass through the substrate layer. Furthermore, the substrate layer can be made of a material with a relatively large resistivity and relatively poor conductivity, while the other layers grown above the substrate layer are relatively thin and easy to electrically isolate. Furthermore, the two adjacent laser segments are separated by the electrically isolated segment with a relatively large resistivity and the substrate layer with a relatively large resistivity, thereby avoiding the problem of electrical signal crosstalk between the two adjacent laser segments.

[0157] This embodiment also provides a light emitting device. As described above, the laser chip is a bare chip. The laser chip can be packaged and used in the light emitting device. The laser chip can be packaged in a TO package or a BOX package.

[0158] This embodiment also provides an optical module, wherein the optical emitting device includes the aforementioned optical emitting device, a circuit board, a driver circuit, and other components. The optical module can be a transmitting optical module or a receiving optical module. The optical module can be used in a passive optical network (PON) or in an online fiber optic detection system.

[0159] For example, the optical module is used in PON because the laser chip of the optical module can emit lasers at different rates, for example, it can emit 2.5Gbit / s lasers and 10Gbit / s lasers, thereby realizing the coexistence of GPON and 10GPON in the passive optical network.

[0160] For example, this optical module is used in an online fiber optic detection system. Because the module's laser chip can emit lasers at different rates, for example, it can emit normal signal light and detection signal light. The normal signal light and the detection signal light have different wavelengths, allowing the two signals to operate simultaneously without interfering with each other. By measuring the return signal of the detection signal light, attenuation information is obtained, which indirectly measures the loss and fault location of the optical cable, thus enabling online fiber optic fault monitoring without affecting normal optical communication.

[0161] This embodiment further provides an optical communication system, which includes a communication device and the optical module described above. The optical module can be connected to the communication device in a pluggable manner, and the optical module can also be integrated into the communication device.

[0162] The optical communication system may be a PON system or an online optical fiber detection system.

[0163] The above description is only one embodiment of the present disclosure and is not intended to limit the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure should be included in the scope of protection of the present disclosure.

Claims

1. A laser chip, characterized in that: The laser chip comprises a substrate layer (1), a first electrode contact layer (3), a first electrode layer (4), an active layer (6), a ridge waveguide layer (9), a second electrode contact layer (10) and a second electrode layer (11); The first electrode contact layer (3) is located on the upper surface of the substrate layer (1), and the first electrode layer (4) is located on the upper surface of the first electrode contact layer (3); The active layer (6), the ridge waveguide layer (9), the second electrode contact layer (10) and the second electrode layer (11) are sequentially stacked on the upper surface of the first electrode contact layer (3); The laser chip is a multi-segment laser chip, which comprises a plurality of laser segments (A) and at least one electrical isolation segment (B) in the light transmission direction, wherein the electrical isolation segment (B) is arranged between two adjacent laser segments (A), and the electrical isolation depth at least extends to the lower surface of the first electrode contact layer (3).

2. The laser chip according to claim 1, characterized in that: The material of the substrate layer (1) is semi-insulating material.

3. The laser chip according to claim 1 or 2, characterized in that: The first electrode layer (4) and the second electrode layer (11) both have a distance between them at the electrical isolation section (B).

4. The laser chip according to claim 3, characterized in that: The first electrode contact layer (3) and the second electrode contact layer (10) both have a spacing at the electrical isolation section (B), and the spacing position of the first electrode contact layer (3) corresponds to the spacing position of the first electrode layer (4), and the spacing position of the second electrode contact layer (10) corresponds to the spacing position of the second electrode layer (11).

5. The laser chip according to any one of claims 1 to 4, characterized in that: Ions are implanted into the electrical isolation section (B) for increasing the resistivity of the electrical isolation section (B).

6. The laser chip according to any one of claims 1 to 5, characterized in that: The laser chip further comprises at least one light processing section (C), wherein the light processing section (C) is arranged between two adjacent laser sections (A); The light processing section (C) is used to reflect the laser light emitted by the laser section (A) located between the light output end and the light processing section (C), and to transmit the laser light emitted by the laser section (A) located between the backlight end and the light processing section (C).

7. The laser chip according to claim 6, characterized in that: If one of the light processing sections (C) is arranged between two adjacent laser sections (A), then the electrical isolation section (B) is arranged between the laser section (A) and the light processing section (C); If a plurality of light processing sections (C) are arranged between two adjacent laser sections (A), the electrical isolation section (B) is arranged between the laser section (A) and the light processing section (C), and between two adjacent light processing sections (C).

8. The laser chip according to claim 7, characterized in that: The optical processing section (C) is a phase modulation processing section, an electroabsorption processing section or an amplification processing section.

9. The laser chip according to any one of claims 1 to 8, characterized in that: The laser chip further comprises a first electrode pad (12) and a second electrode pad (13), wherein the first electrode pad (12) is electrically connected to the first electrode layer (4), and the second electrode pad (13) is electrically connected to the second electrode layer (11); The first electrode pad (12) and the second electrode pad (13) are located on different sides or the same side of the ridge waveguide layer (9).

10. A light emitting device, characterized in that: The light emitting device comprises the laser chip according to any one of claims 1 to 9.

11. An optical module, characterized in that: The optical module comprises the light emitting device according to claim 10.

12. An optical communication system, characterized in that: The optical communication system comprises a communication device and the optical module according to claim 11, wherein the optical module is connected to the communication device in a pluggable manner, or the optical module is integrated in the communication device.

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